NECTAR CONSUMERS - Nectaries and Nectar - page 327

greatest discrepancy appears to be between the 60% optimum recorded for
glossophagine bats and the low average nectar concentration measured for
bat flowers (Roces et al., 1993). However, the same study showed that under
laboratory conditions these bats drink free water, especially when rehydrat-
ing at the beginning of the night, and many pollinators may have high water
requirements. Even bumblebees, which usually maintain water balance on
very concentrated nectars, have been observed collecting water in warm
weather (Ferry & Corbet, 1996).
The ability of nectar consumers to cope with nectars of varying concen-
tration and composition is an advantage when nectar varies greatly in quality
and quantity and when its consumers must compete for limited resources.
The physiological adaptability of nectar consumers is also compatible with
the concept of widespread generalization in many pollination systems
(Waser & Ollerton, 2006). Differentiation is more likely to be determined by
secondary compounds in nectar that attract or deter particular consumers.
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